title: Improved properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) produced by Comamonas sp. EB172 utilizing volatile fatty acids by regulating the nitrogen source.
abstract: This study presents the effect of carbon to nitrogen ratio (C/N) (mol/mol) on the cell growth and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) accumulation by Comamonas sp. EB172 in 2 L fermenters using volatile fatty acids (VFA) as the carbon source. This VFA was supplemented with ammonium sulphate and yeast extract in the feeding solution to achieve C/N (mol/mol) 5, 15, 25, and 34.4, respectively. By extrapolating the C/N and the source of nitrogen, the properties of the polymers can be regulated. The number average molecular weight (M n ) of P(3HB-co-3HV) copolymer reached the highest at 838 × 10(3) Da with polydispersity index (PDI) value of 1.8, when the culture broth was supplemented with yeast extract (C/N 34.4). Tensile strength and Young's modulus of the copolymer containing 6-8 mol% 3HV were in the ranges of 13-14.4 MPa and 0.26-0.34 GPa, respectively, comparable to those of polyethylene (PE). Thus, Comamonas sp. EB172 has shown promising bacterial isolates producing polyhydroxyalkanoates from renewable carbon materials.
authors.affiliation: Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
authors.forename: Mohd Rafein
authors.initials: MR
authors.lastname: Zakaria
authors.forename: Hidayah
authors.initials: H
authors.lastname: Ariffin
authors.forename: Suraini
authors.initials: S
authors.lastname: Abd-Aziz
authors.forename: Mohd Ali
authors.initials: MA
authors.lastname: Hassan
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Shirai
mesh_terms: D002244:Carbon / Q000737:chemistry*; D020585:Comamonas / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D005232:Fatty Acids, Volatile / Q000737:chemistry*; D005285:Fermentation; D008970:Molecular Weight; D009584:Nitrogen / Q000737:chemistry; D011091:Polyesters / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D000094122:Polyhydroxybutyrates
chemical_list: D002244:Carbon; D005232:Fatty Acids, Volatile; D009584:Nitrogen; D011091:Polyesters; D011108:Polymers; C052620:poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate); D000094122:Polyhydroxybutyrates